TREVISO, Italy — On New Year’s Eve, Antonio Tamiozzo, 53, hanged himself in the warehouse of his construction business near Vicenza, after several debtors did not pay what they owed him.

Three weeks earlier, Giovanni Schiavon, 59, a contractor, shot himself in the head at the headquarters of his debt-ridden construction company on the outskirts of Padua. As he faced the bleak prospect of ordering Christmas layoffs at his family firm of two generations, he wrote a last message: “Sorry, I cannot take it anymore.”

The economic downturn that has shaken Europe for the last three years has also swept away the foundations of once-sturdy lives, leading to an alarming spike in suicide rates. Especially in the most fragile nations like Greece, Ireland and Italy, small-business owners and entrepreneurs are increasingly taking their own lives in a phenomenon some European newspapers have started calling “suicide by economic crisis.”